The present invention relates to washing machine draining and recirculation systems. Particularly, the invention relates to a vertical washing machine having filtering apparatus for lint removal and particularly to a combined self-cleaning filter and drain manifold for an automatic washing machine having a reversible hydraulic circuit for circulating laundry liquid first in one direction during a washing operation and then in an opposite direction during an extracting and draining operation.
A combination drain manifold and self-cleaning filter arrangement for a washing machine is disclosed in U.S. Pat. No. 3,681,947. In that patent, a combined drain manifold and lint filter assembly is disclosed connected directly to a drain port formed in a tub of an automatic washing machine. The lowermost wall of the drain manifold is formed by a flexible wall of a self-cleaning diaphragm filter so that the static water head pressure from the tub acts on the filter diaphragm to keep it closed without a backup plate or springs. Fluid entering the drain manifold is directed downwardly, across a side of the diaphragm opposite the filtering chamber then upwardly to an exit port, thereby flushing the drain manifold of sand and other small particles while trapping larger items such as buttons.